I posted a reference to a paper on calculating the volume of Nurbs objects a while back. So it is possible...
The Nurbs integral calculus mathematics was difficult, or pretty nearly incomprehensible, :-) and the Nurbs formulas get manipulated,
which I think only Michael could do? (I suppose some sort of cross section estimation could be made.)

- Brian

( The old link was bad, here is another link:)
http://www.me.berkeley.edu/~mcmains/pubs/SPM2010KrishnamurthyMcMains.pdf

Download the evaluation version of Rhino. It has a built-in volume analysis tool; which should not be affected by the time limits.

Minimagics 2.0 by materialise is an stl checker that will give the volume and is free.
cheers
shayne

I think there is no need to write a script for exact calculation of volume.
99% accuracy should be enough. I can write such a script very easily.
I have checked two methods today, but I found that some moi functions doesn't work as I need.


Here is the issues:
1. Boolean Isect doesn't work with solid and line.
2. Curve Isect generates many wrong points of intersections in some cases.

The last way which I can use is Trim function.. I'll check it.

Hi Max,

> 1. Boolean Isect doesn't work with solid and line.

It seems to work over here but probably does not do what you need - the way the booleans work with curves interacting with solids is that the curve is extruded out into a surface and then it's that extrusion that interacts with the original solid.


> 2. Curve Isect generates many wrong points of intersections in some cases.

Can you post a 3DM file? I tried a box with diagonal line like you've got there and I got 2 points.

- Michael

Hi Michael,

the file attached to my previous message. Curve Isect generates 14 points.

Hi Max, sorry I must have missed the attachment.

I'm not sure why there is no result from boolean intersection there, but even if it did work it would work as it does in the attached version.


re: 14 points - sorry I didn't notice there were so many points stacked up when I tried it. It's likely to be coming from multiple pieces of the solid's topology all intersecting the line there, probably results from 3 faces, 3 edges and 1 vertex all intersecting the line right there. The geometry library function that is being called for the intersection seems to return all those results and that's what gets generated currently. In v4 I should be able to filter results like that to weed out duplicates.

- Michael

Volume calculation in MoI would be great. I create a lot of stuff for 3D printing, and now have to export a mesh to Blender 3D first, to measure its volume using the 3D Print Toolkit add-on.